70 THE AIM AND ACHIEVEMENTS OF SCIENTIFIC METHOD. 



subsidiary descriptive notions such as Harmonic Vibration. 

 Similarly, the chemist seeks to bring other Objective happen- 

 ings under the concept of Equivalence, while the biologist 

 will employ in a similar manner the notion of Natural Selection 

 or of Panmixia. These attempts to bring the particulars of 

 experience under such special concepts may one and all be 

 called " final explanations " ; the purpose which makes that 

 term appropriate being, of course, the conscious endeavour of 

 the investigator to apply this special form of solution to the 

 problems before him. On this "view, then, all the special 

 interpretations of the sciences are final explanations ; while 

 all are to be regarded as subordinated to the general notion 

 of causal explanation, in so far as they aim at exhibiting the 

 dependence of the behaviour of things upon external conditions. 

 In conclusion, attention should be directed to the fact that 

 we are here concerned only to maintain the right of every 

 investigator to choose his own weapons wherewith to reduce to 

 intelligibility the primary facts within the province of the 

 Objective which he has marked out for conquest. Upon the 

 subject of the choice at any particular stage in any of the 

 special sciences each such science must be " self -normative." 

 This contention does not forbid us to hold, with Professor 

 Boyce Gibson,* that, on the whole, " the essential discovery 

 of modern science is that its ideal, the thorough understanding 

 of nature, can be reached only by subordinating the idea of end 

 entirely to that of law," nor yet to. agree with Lotzef in feeling 

 " certain of being on the right track, when [we] seek in that 

 which should be the ground of that which is."J 



* A Philosophical Introduction to Ethics, p. 53. 



t Metaphysics, ii, p. 319. 



J I much regret that the extremely interesting little book on The 

 Interpretation of Nature", by Professor Lloyd Morgan, did not fall into 

 my hands until after the above discussion had been written. I may, 

 perhaps, be allowed to refer the reader for a fuller discussion of the origin 

 and import of the causal concept to my paper " On Causal Explanation ' 

 in the Proceedings of the Aristotelian Society for 1906-7. 



